The nonlinearity of trade variables such as trade balance, real effective exchange rate, domestic output and foreign output has been checked. Further Marshal Learner (ML) condition has been examined through linear and nonlinear models such as Threshold autoregressive (TAR) model and long run relationship checked through threshold hold cointegration developed by Enders and Siklos (2001) for the time period 1982:01-2014:04. Further, asymmetric adjustments give different coefficients of long run adjustment on the basis of threshold level of real effective exchange rate. Supervisor:- Dr.Nasir Iqbal